Method of direct recovery of tar and ammonia from distillation-gases.



W. MUELLER, GOWEB? 0F TAR AND mmm U1, FRG'M, DSTlLLATON APPLICATION HLBD M1138, w11.

METFD OF DIRECT RE QW b ha SHEETS-SHEET l.

Paente. No?" 5,

iN *f N 1.39;

vWIT/M'LTSSE W. MUELLER. METHOD OF DIRECT RECUVERY 0F TAR AND AMMONIA PROM DISTILLATION GASES.

W. MUELLER. METHOD OE DREGT REGOVERY 0F TAR AND AMMONIA FROM DISTILLATION GASES.

APPLIGATUN FILED APRY 1B, 1911.

Patented. Nov. 5, MM2.

4 SHEETSfSHEET 3.

i i w15 H MU WK- W. MUELLER.

METHOD 0F DIRECT RECOVERY OP TAR AND AMMONIA PROM DISTILLATION GASES.

APPLICATION FILED 11173.18, 1911` Patented Nov. 5, 1912 4 SHEETS-SHEET 4.

v INVENTOR: MMM/VW d/uvb,

throughout the drawings.

WILHELM MUELLER, 0F ESSEN-QN-TH-EHR, GERMANY.

METHOD GF DDfECl RECVERY 01E TAR AND .MHNIA FRM BISTELLTON-G'SES.

Specication of Letters Iatent.

atented Nov. 5, 191i?.

1910, Serial No. 53E/tst). Divided and this application filed April 19, 1911. Serial No. @$1,570.

To all who/m it 'may comem:

Be it known that I, WILHELM MUELLnn, a citizenv of Germany, residing at 17 Gutenbergstrasse, Essen-on-the-Ruhr, Germany,

5 have invented new and useful improvements in Methods of Direct Recovery of Tar'und Ammonia from Distillation-Gases, 'of which the following is a specification.

My present invention relates to a method 0r process of recovering successively oil, tar and ammonium sulfate from hot distillation gases of coal or other fuel, and has for its object to simplify the operations, lto reduce to a minimum the power required for Working, to produce perfectly pure tar and sulfate of ammonia in a direct manner Without the use of steam or lime, and to reduce the initial outlay for the plant and the Working and maintenance expenses. These improvements relating to a. method represent a d1- vision from the improvements relating to the apparatus which form the subject of m. (zo-pending application Seria-l No. 580,440, filed September 3rd, i910.

' The invention is, for example, illustrate-d in the accompanying drawings of which--- Figure 1 is a diagrammatic view of a suitable plant for treating the gases according to the improved method; Fig. 2 shows to a larger scale the apparatus marked A. B in Fig. 1 for cooling and washing the hot gases for the purpose of removing the tar, oil or benzol; Figs. 3, l and 5 illustrates various constructions of the grids or hurdles which may be used in the apparatus shown in Fig.

2; Fig. 6 shows in sectional elevation and to a larger scale the saturator marked S in Fig. 1 which is used for freeing the gases which havei passed the Washer shown in Fig. 2 from ammonia and recovering the latter in the form of sulfate; Figs. 7 and B are transverse sections on lines X-X and Z-Z respectively in Fig. 9; Fig. 9 is a plan of the apparatus shown in Fig. 6; FigrlO is a part section showing birdie-plates. pivotally mounted on the fiat top of the saturatingchamber; Fig. 11 illustrates a modied construction of the saturator; Fig. 12 is a vomical section and Fig. 13 a horizontal section l through the apparatus shown'in Fig. 11.

Like reference letters indicate like parts The process of treating .apparatus-1s as follows z-In order to remove theby-products, more especially the the gases in the tar and the ammonia, from colte-oven or distillation gases of coal or other fuel in a direct manner, it is essential first to separate the tar and other impurities from 'the hot gases, so that during the passage ort the gases through the sulfuric acid bath in the saturator the ammoniacal-salts shall not he polluted by terry substances and rendered unsalable. To attain this the hot gases which come direct from the ovens or retorts 0 and are somewhat cooled in the collecting mains V and thev pipes, are introduced at a temperature of about 200 degrees centigrade into the apparatus W. The gases pass ,through the pipe l and enter theiupper end of the outer chamber Ayand descend to the openings 9 through which they pass to the fan 8 which forces them up into the Washer. During their passage through the outer' chamber the gases cool down to a temperature of about 100 degrees C., the maior part of the tar, dust and other impurities being condensed and separated from the gases. To prevent the formation of tar or dust de- .posits on the sides the latter may be sprinkled with for example gas water and thin tar from the top by means of the spray nozzles 6. The Vgases now pass upward through the washer B containing improved hurdles yor grids C.D or E of the constructions shown in Figs. 3, a and 5. 0n passing over these hurdles the gas is repeatedly split up into numerous fine streams and is uniformly distributed throughout the Whole space of the Washer @Wing to the increased velocity imparted to the gases by the propeller or fan 8, and the fact that the gases strike many times against the horizontal surfaces of the grids or hurdles all solid and liquid substances are separated according to the principle of condensation by shock which is involved in the Pelouse apparatus. Since the hurdles are continuously sprayed .from above and, allv surfaces are moistened byv the liquor, the gases, in addition to the separating action due to the repeated impact, are brought into intimate contact withY the Washing-liquor andere therefore oiieetuall 'puriied The purified gas passes throng the screens o arranged in the top part oi the washer, which screens retain. even the slightest traces of Water, and escapes in a dry, hot state say at a temperature of about 75 C. through the pipe 10 leading direct to the seturator S. j

Washed. By introducing the second period only into the upper portion of the Washer the further advantage is attained that the hot gaswater (or thin tar) used as Washing liquor is still further heated whereby the ammonia constituents contained in the gas-water are vaporized and caused to escape together with the gas. The hot gas still charged with all the ammonia combinations is passed from the Washer lV through pipes l() and 11 directly into the sulfuric acid bath of the saturator S, see Fig. 6 or Fig. 11. It enters the bath through the widened end of" pipe 12 with its d1stribution hoods l2ci or through a number of smaller pipes 13, bubbles up through the bath to the top 15 of the saturator,v and then moves in a thin and wide stream over the surface of the bath to the exit. Since the ammonia is not completely absorbed during thefirst passage through the acid, the gas is compelled to pass repeatedly through the acid by the baille-plates 16 which di into the bath and are inclined in the direction of the gas current. The result of this arrangement is that on the one hand all the ammonia contained in the gas is completely absorbed and on the other hand the upper zoneof the bath is given a continuous forward movement. On account of the latter all the impurities collecting on the surface, such as tar-froth or the like, are carried toward the end ct the bath and caused to into the froth-chamber 19 from which they run outward into a tank ory Cask through a pipe 20.

The liquor carried together with into the chamber 19 returns to the bath through the screens 19a at the bot-toni. In this Waythe surface of the bath is always kept in a clean condition. The concave inner surface 18a` her 19 dedects the ,l in the downward direct-ion as in Fig. 6, or f in the lateral directions as in Figs. ll, l2 i and l3`(by means of surfaces 18b` and 24). Owing to this circulation the upper zone of the acid bath is thoroughly stirred and the etliciency iss-increased while the consumption of the acid is reduced to a minimum;

The products of condensation obtained by the cooling and washing of the gases, viz. ust, tar, oil and gas-water collectin the bottom part of the apparatus `W from which .5 they automatically run through a Siphon pipe 9a to a settling tank wherein separation according to. specific gravity takes place. The recovered gas-water and, if required, also the light thin tar-may advantageously by pumped to the top of the apparatus and used again as washing liquor, in which case they may be introduced through the spraying nozzles 6.' The excess of gas-Water lwhich cannot be used is supplied without any further treatment to the acid bath of the saturator. The hot gases passing through the outer chamber A. keep the inner chamber of the washer at a constant high temperature which may be regulated in such a manner that the gases leave the apparatus at a temperature of about 70-80 degrees C. at which temperature all the ammonia still remains volatile. For this reason, hot condensed gaswater or hot thin tar should be employedfor spraying the hurdles so as to el'ect the Washing of the gases without condensing the ammonia constitutents. L

When distilling coal or other fuel which produces gases very rich in tar, it is preferredf to collect fthe gases in two .fractions corre ending to about the iirst three fourths and t e last quarter of the period of distillation, separate mains being used for ,the two fractions. This manner off-collecting the gases is not in itself new. While however it was hitherto usual to wash these two fractions separately, or not to wash the gas of the latter period at all, according to the present'prbcess both kinds o gtjgas are washed `simultane/ously. For this purpose the gas obtainedduring the first three fourths of the disti'llatinf, which gas contains most of the tar and the impurities is introduced at the top through pipe 1 so that it has to pass through'the Whole of the apparatus in the mannen already described. he gas produced during the last quarter of the distil- 50 latln is then introduced through pipe 2 and it mixes with the gases produced during the first three fourths of the distillation proc` ess already treated in the lower part of the washing'apparatus, and is subjected therewith simultaneously to the washing action. gases of the last period vent condensation of the aqueous vapors contained in the gas, ber is heated at the sides by means ofthe steam pipe coil sp and the additional sul-- uric acid or other satura tor at a high temperature through pipe whereby, the reajion heat is in By the introduct o luric acid from the reservoir 27 through ipe 29 and nozzle 30 direct into the gas inlet pipe 12 of the saturator a more intimate intermingling with the and a quicker absorption of the ammonia is ettained.

s 1s Well-known the tus, if t e gases of both periods are treated simultaneously. This drawback is however,

obviated if the gases enter the apparatus! separately and are mixed only after theI ttf of the rst period are more than half A the hot gases of of the wall 18 of the cham` stream of liquor, either 1 F or the same purpose and in order to pre-' pass over the Wall 18 the froth the saturatingchami liquor is supplied `to the n of hot sul- I the solid Salts of ammonia carried forward by the circulation of the bath and cause the salts to settle. These perforated plates 21 are arranged in the construction according to Figs. 11 and 13 near the entrance and in the lateral passages 22.

The crystallizing solid salt of ammoniaproduced in the saturator by the reaction of the ammonia upon the sulfuric acid drops into the lower collecting chamber 25 and is lifted in a Well known manner by meanslof a steam ejector 26 to a draining tablel from which latter it is delivered to thecentrifugal drying machine 32 which leaves the salt in a salable condition and ready to be stored. The separated lye or liquor runs into a liquor-pot 33 which automatically returns the liquor to the bath in the saturator for further treatment. The gases which areentirely purified from tar and ammonia are finally drawn'from the saturator through an acid separator 34 and pipe 35 by means of an cxhauster 36 which forces them into a gasometer in which they are stored to be used for illuminating, heating or motive-power purposes.

The new method of` producing the. ammonia in a direct manner Without the aid of steam or lime enable the recovery of the ley-products to be effected in a much more economical Way than hitherto, and has the further advantagethat the employment of the usual arrangement for Washing' and distilling with their inevitable poisonous effluent liquor and mudv nuisance is entirely dispensed with.

1. Process of direct production of tar andv ammonium-sulfate from distillation ygases of coal or other fuel consisting in collecting the gases in two fractions, one fraction being collected during about the iirst three fourths and the other during the last quarter of the distillation period, introducing the first fraction into the washer in such a mann-er as to cause the said first fraction to pass through thc whole space of a coolingV and washing apparatus and introducing thesecond fraction into the center of the inner washing chamber so as to mix With the half Washed gases of the first fraction, both fractions being then simultaneously `Washed and treated together as described in the upper portion of the Washing chamber. A

y2. Process of direct recovery of tar and ammonium-sulfate from .distillation gasesV of coal or other fuel consisting in cooling the hot gases coming direct from the ovens 'or retorts to about 70 to 8O degrees C.,

Washing the gases by means of the prieviously condensed hot liquor, splitting the volume of gases during washing into a number of fine streams, passing the gases at the aforesaid temperature immediately after washing into and through the sulfuric vacid bath ofa saturator in which the ammonia is recovered in the form of sulfate and supplying to thebath additional sulfuric VLacid at a high temperature.

3. .Process of direct production of. tar and ammonium sulfate from distillation gases of coal or other fuel coming directly from the ovens or retorts, consisting in cooling the hot gases to about 70 to 8O degrees C., smultancously Washing the gases in a ivashin'g chamber on the counter current principle by means of the previously condensed hot o gas liquor meanwhile splitting the 8c volume of gas to be Washed into a number of line streams and causing the latter to perform a tortuous course and to have re* peated impact with surfaces. obstructing their path whereby all tar and oily substances are mechanically separated, and

passing the gases at the aforesaid tempera-I ture immediately after Washing through the sulfuric acidl bath of a s aturater wherein the ammonia is recovered in the form of sulfate, supplying the sulfuric acid to the saturator at a high temperature and supplying additional sulfuric acid at a high temperature into the gas inlet pipe of the saturator.

In testimony-whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WILHELM MUELLER. lVitncsses Amin-in HENKEL, MAX Gniiconic. 

